Algorithms and architectures for robust video transmission.

摘要

The demand of transmitting video through the Internet and mobile channels has increased significantly in the last several years. The compressed video bitstream is vulnerable to a small amount of bit error or packet loss. Joint source and channel (JSC) coding techniques have been proposed to protect transmitted video data. In most JSC coding techniques, distortion estimation due to packet loss is performed. In this research, a corruption model is proposed, which can be used to enhance the performance of various JSC coding techniques as a distortion estimation tool.; The loss impact of each Macroblock is analyzed in this research on the corruption model by taking into account error concealment, temporal dependency, and the loop filtering effect. In addition, we extend the corruption model to cover more general error propagation behaviors, and apply it to jointly coordinate adaptive intra refresh (AIR) and unequal error protection (UEP) for robust video transmission.; The personal mobile communication system that communicates with the video transmission capability is enabled by extensive research on robust video compression and transmission. However, the complexity of the compression algorithm is also significantly increased. The System-on-Chip (SoC) design for mobile devices is very difficult due to its complexity and the associated verification problem. In this research, we present a design approach that is more flexible while achieving a high performance. The Xtensa processor is a configurable embedded processor for SoC that allows users to design their own instructions to accelerate the computational speed.; The instructions are designed for computationally intensive modules first. The instructions can be the form of either the Single Instruction Multiple Data (SIMD) instruction or the Multiple Instruction Single Data (MISD) instruction. Then, the overall encoder software structure is optimized to avoid the penalty of cache misses in the frame memory access based on the investigation of the memory system of the embedded system.; The improved MPEG-4 encoder software and processor can be used practically for SoC design with the external memory as the main memory, which can reduce the system cost compared to the use of a large internal memory.